Compensator and method



Dec. 1-5, 1936. G.. w. PIERCE ET ,AL

COMPENSATOR AND METHOD Filed June so', 1955 2 Sheets-Sheet l G. W. PIERCE l' AL Dec. 15, 1936.

COMPENSATOR AND METHOD Filed June 30, 1933 2 Sheets-Sheet'.22`

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Patented Dec. l5, 1936 UNITED STATES PATENT OFFICE COMPENSATOR AND METHOD George Atherton Noy Jr., Noyes assignor to sai Application June 30, 1933, Serial No. 678,482

Claims.

The 'present invention relates to vibratory methods, systems and apparatus, and more particularly to electrical systems and apparatus employing electromechanical vibrators. From a 5 more limitedv aspect, the invention relates to the transmission and reception of intelligence, using sound waves as the agency of communication,

and is an improvement upon the invention illustrated and described in application Serial No. 684,200, led August 8,/ 1933. 'I'he term sound will be employed hereinafter, in the specication and the claims, to include the supersonic, aswell as the audible part of the sound spectrum, and to include also all kinds of elastic vibrations. 'I'he invention, indeed, finds particular application to supersonic communication.

The primary object of the invention is to provide a new and improved compensator for the transmissionand Areception of sound in any selected direction.

A further object of the invention is to provide a directionally selective` transceiver for submarine communication and direction iinding which can be permanently fixed in position and which operates Without the necessity of bodily rotation.

With the above ends in view, a feature of the invention resides in the use of a number of small transducersdisposed side by side, having individuairadiatingfaces, and with magnetostric` tive windings slidable along magnetostrictive wires attached to the individual transducers.

Other and further objects will be explained hereinafter, and will be particularly pointed out in 4the appended claims.

The invention .will now be explained in con- `nection with the accompanying drawings, in which Fig. 1 is a plan of a preferred embodiment of the improved compensator of the present invention; Fig. 2 is a fragmentary plan of the same, upon a larger scale; Fig. 3 is a broken, enlarged, longitudinal section, taken upon the line 3 3 of Fig. 1, looking in the direction of the arrows; Figs. 4 and 5 are further enlarged, transverse sections, taken upon the lines 4 4 and 5 5 of Figs. 2 and 6, respectively, looking in the directions of the arrows; Fig. 6 is a fragmentary plan similar to Fig. 2, sho'wing the parts in relatively different positions; Fig. '7 is a view 50 of a modication; and Fig. 8 is a section, taken upon Athe line 8 8 of Fig. 7, looking in the direction of the arrows.

A plurality of transducers I, 2, 3 I3, are each mechanically connected with a wire core I6,

55 I1, 28, preferably of nickel, nickel-steel,

nickel-copper, nickel-cobalt, chrome-nickel, chrome steel, or of any other metal element or alloy characterized by comparatively large magnetostrictive effects. The cores are parallel to one another, and each is shown positioned sub- 5 stantlally in axial alinement with, and magnetostrictlvely coupled to, a picked-up coil 50, as a suitable mechanism for obtaining electric current or voltage from the mechanical vibrations of the cores I6 to 28, or vice versa. The 10 coils 50 are shown connected together in series by exible conductors I 0| and 200, but may, of course, be connected in parallel, or in any seriesparallel combination, as desired. The coils 50, which interact magnetostrlctively with the cores 15 I6 to 28 to develop voltages in the coils in response to vibrations in the cores and to produce vibration of the cores by the action of the magnetic field produced by current in the coils, will be referred to, in the specification and the claims, under the broad heading of interactors. An interactor may here be defined broadly as a device permitting and causing the interaction of mechanical vibrations with electric currents and voltages for the transformation of energy from one form to the other. 'I'he voltage or current developed may be fed from, or into, an oscillator or receiver 42, the former for transmission purposes and the latter for reception. The oscillator may serve as a source of high-frequency, electric oscillations for producing the mechanical vibration in the wires I 6 to 28, and may be of any desired type, such for example, as is illustrated and described in United States Letters Patent 1,750,124, issued March 11, 1930.

Polarizing magnets (not shown) may be employed in connection with the magnetostrictive wires I 6 to 28 or, preferably, the polarizing eld may be obtained by passing a direct current through the pick-up coils 50. The oscillator or receiver 42 is tuned, as by means of tuning condensers (not shown), to the same frequency as the frequency of the soundbeam signal, or to a desired component of the sound frequency. 45

The transducers I to I3 are provided with their faces lying in a plane and along a line of length sufiicient, in relation to the Wave length of sound in the medium, to give sharp directional discrlmination. The spacing between cen- 5o ters of adjacent transducers should not be greater than one half-wave length of sound in the medium at the highest frequency to be employed. Otherwise the compensator will have multiple angles of response.

- in number than here illustrated.

\ is radiated The transducers I to I3 may be fewer or more in number than illustrated, and may be of any desired form, the conical'form forming the subject matter of Patent No. 2,044,807. The sound to or from the large end of the cone, the magnetostrictive cdre I6 to 26 that drives it, or that is driven by it, being secured to the small end. For reception and transmission of sounds of any desired frequency, particularly high frequencies, through the water or other elastic media, the large ends .of the tranducers I to Iswill be submerged in the ocean. According to the preferred arrangement, the transducers are shown disposed side by side, but out of' contact with one another, at uniform intervals along a substantially straight line, attached to a common supporting base 58, which may be the side of a ship, and with their larger ends facing in a common, predetermined direction.

The array of transducers may be in a single line, as illustrated in Fig. l, in which case the compensator will have good directional selectivity for signals arriving at angles lying in the plane of the paper, but substantially no selectivity for signals arriving `at angles lying in a plane perpendicular to the plane of the paper. If it is desired, as in the case of communicating between ships, to transmit or receive most eiliciently in the plane of the paper, it will be necessary to give the array of transducers a dimension perpendicular to the plane of the paper large in comparison with the wave length employed. This may be done by forming the array of a number of .I

parallel, linear arrays,'with the faces of the transducers all lying in the same perpendicular plane, as shown in Fig. 7, and in cross section in Fig. 8. Corresponding units of the linear arrays should then be joined by sound conducting wires, of equal length, to the appropriate retarding wires I6 to 28.

A composite, acoustic-energy converter Yis thus provided, having a large number of transducers I or I3, all separated from one another, yet all free to `vibrate to produce a common, enhanced effect. The transducers, of course, may be more or fewer The arrangement of theV coils permits of their proper positioning to take advantage of the various cooperative effects of 4the vibrator wires I6 to 26. In reception, assuming, for example, a beam of particular, high-frequency sound, modulated or unmodulated, below and to the right of Fig. 1, the incident sound beam, directed, for example, from .a distant sending station (not shown) at an angle tothe line "of" transducers vI to I3, located at a receiving station, such as a ship, will impinge on the transducers I to I3 in numerical order, beginning with the lowermost transducer I. The transducers will all become excited into vibration, in `numerical sequence. Mechanical vibrations will, first, begin to travel along the wire I6, connected with the lowermost transducer I, toward its coil 50, before they do so in the wire I1, connected with the next transducer 2, and so on. By the time that the sound impulse has reached the last transducer I3, the mechanical vibrations will have traveled along the wire I6 a. predetermined distance, `along the next wire I1 a smaller distance, along the wire I8 a still smaller distance, and so'on. The wires I6 to 28 thus serve as retardation wires for transmitting a particular, selected frequency of mechanical vibration. If the coils 50 are so axially'adjusted along the retardation wires I6 to 28 that the mechanical vibrations, traveling along the wires, shall be S retarded as to reach the various coils 50 at the same moment, the coils 50 will operate in synchronism to convert the mechanical vibrations, by magnetostriction, into electrical energy, thereby to produce an enhanced eect as'to intensity.

The sound impulses will thus add together at the coils 50, positioned .to receive this signal as a maximum and connect it -into an electrical voltage which is fed into the receiver 42. Sound impulses from other sources, having a different ori entation with regard to the array, will arrive out of phase with each other at the coils 50 and add to give a zero or very weak combined signal.l

Similar considerations will apply for transmission, the sound impulses leaving the transducers I to I3 at adjustable time intervals in similar manner and thereby combining to produce a beam of sound which may be rotated at will by adjustment of the angular position of the line of This arrangement is an important element in a direction finder.. As the line of coils 50 occupies a given angle, correspondingto maximum response to a given direction of the sound beam in the medium, it is possible to determine the direction of the sound beam; and as departure from the said angle carries with it a smaller degree of response, it is possible to obtain a very sharp determination of direction. The invention finds also many other uses, such as range finding.

If the transducers I to I3 are arranged at equal intervals along a straight line, the sound waves will, of course, arrive at the transducers at successive, equal time intervals apart. In order that the coils 50 may reinforce one another, they should be spaced along the magnetostrictive cores I6 to 26 at proper intervals apart, along a substantially straight line, to the sound beam, will vary with the direction of the sound beam to be transmitted or received. In reception, for example, the angle of the line of coils 50 should be such that the coils 50 shall be energized in phase. If the sound happens to be incident normal to the array of transducers, the apparatus will give maximum response when the line of coils is parallel to the line of transducers. If the incident sound arrives from any other direction, maximum signal will be obtained when the line of coils is so positioned that the time of arrival of any given sound pulse, suitably retarded in each of the wires I6 to 26, is the same at all the coils 50.

The impulses received at different instants at a number of sound receivers are thus delayed in such manner as to bring all the separate impulses together at a common listening point at the same instant. From the period of delay introduced in each of the various lines, the angle of incidence of the sound is determined. Compensating devices have heretofore been operated at low, audible frequencies, and the retardation has been introduced, for example, electrically, or by means of speaking tubes of` variable lengths. The present invention-deals with new and improved apparatus, employing wires or small-tubes as sound conductors for obtaining the desired retardatirns. Longitudinal sound vibrations in these wires travel with constant velocity from the terminal unit I (say) to coil 50, and the time retardation introduced in this wire, therefore, is directly proportional to the length of wire lying between the transducer I and its coil 50.

It is very important, in any type of compensator, to prevent reflections of energy from the ends of the retardation lines. 4In other words,

the inclination of which,

sound energy. passing by the coil 58 and arriving at the end of the wire, must not be allowed to reilect and return a second time to the coil. If this occurs, a standing wave system is set up in the wire and the net result is that for any coil setting the compensator, instead of responding to sounds from one direction only, responds equally to sounds arriving from two directions making equal angles with the normal to the array of transducers, and on both sides of this normal.

We have found it convenient to prevent such reection by enclosing the ends of the wires I8 to 28 tightly in a soft rubber sleeve 34 a foot or so in length, which absorbs and dissipates any sound energy reachi-ng it.

f V4:When magnetostrictive tubes are used in place of wires, damping may be more eiectively obtained by applying a viscous substance, such as rubber, both internally and externally, so that more of the surface of the tube is acted 'upon. The internal friction may be obtained by forcing a soft rubber rod of normally greater diameter than the magnetostriction tube into the end of the tube and allowing it to expand against the walls of the tube. Additional rubber may then be wrapped tightly around the outside of the tube.

The principle of the operation having thus been explained, the illustrated embodiment will now bedescribed, in detail.

The transducers I to I3 are attached to the base 58 by` means of bolts I4, passing throughflanges I5, that are separated from the larger ends of the transducers by very thin webs 28 (Fig. 3), in such manner as not to affect the yibrations ofthe transducer. One end of each of the wires I8 to 28 is secured to the small end of the corresponding transducer and the other end is provided with a tension spring 38 that is held, by means of a bolt 3| to an upright 32. The wires I8 to 28 are thus held taut and straight, parallel ltor one another, as shown in Fig. l. The uprights 32 are shown positioned at varying points of a base member 33. 'Ihe exact position of the upright 32 is not important since the said other ends of the wires I8 to 28 are damped in any suitable manner, as by means of the sleeves 34, so that no appreciable energy is reflected at these ends.

The wires I8 to 28 may very well be replaced by self-supporting tubes of small diameter, in which case the tension springs may be omitted. With either construction, it is important to provide suiilcient clearance at the axes ol' the coils 58 so .that the coils shall not, as they move, rub.on the wires or tubes. Such rubbing of the coils on the sound conductors produces disturbing noise.

, It will be understood that, throughout the specication and the claims, the term wire, as applied to a sound-conducting member, shall apply also to tubes of small diameter.

Underneath each straight wire or tube I8 to 28, and parallel thereto, there is disposed a straight guide track 35, fastened to the base member 33 in any desired manner, as by bolts or screws 38. The tracks 35 *are spaced from the base by spacing members 31, in order that members 38, for carrying or supporting the coils 58, 'may readily be Islidably mounted thereon. Sliding movement of the members 38 upon their tracks 31, therefore, renders it possible Ato adjust the coils 58 along the wires I8 to 28. The corresponding, intermediately disposed, coil-supporting member, over the wire 22, indicated at 48, is held xed, against movement, by a bolt as shown in Fig. 5. 'I'he mechanism will now be described for adjusting the coils 50 as a unit, so that they may always lie in a straight line, suitably inclined to the wires I8 to 28 and, therefore, to the line of transducers I to I3. I

Referring more particularly to Fig. 4, the lower wall of the support 38 is countersunk at 38 to receive the head 48 of a bolt 4|. 'I'he bolt 4| extends freely upward through an opening 33 in the upper wall of the support 38, and that communicates with the countersink 39. A nut 44 holds a iianged, bearing sleeve 45 securely in place on the bolt 4|. A second bearing sleeve 45, mounted over the sleeve 45, between its end anges, is provided with an intermediately glisposed flange 41. Links V48101* a pantograph are pivoted about each bearing sleeve 48, above and below the flange 41. The links 48 are pivoted to each other at 89 (Fig. 6). As the pantograph links 48 are collapsed or extended, therefore, the coil-supporting members 38 are caused to slide along their tracks 35.

'I'he slides 38 are thus caused to move, back and forth, along a diagonally disposed, straight line that always passes through the bolt 5| (Figs. l and 5). The range of movement, both longitudinally and transversely. may be greater than is illustrated in Fig. l. An index 52, that is fast to one of the slides 38, shownas the lowermost slide, may cooperate with a scale 53 to measure the angle through which the coils have been rotated, or it may read directly the angle of the bealm relative to the line of the transducers I to 3.

Each coil 58 is mounted between insulating plates 54, provided with openings 55 through which the magnetostrictive wires I8 to 28 extend. An upward extension 58 of the bolts 4I and 5| passes through one of the insulating plates 54, that is held on the extension 55 by a nut 51. B'nding posts 58, moulded intofthe insulating plates 54, connect with the ends of the coils 58 and are connected with successive coils by the conductors IUI (Fig. 6).

It has been found convenient to make electrical connection to the coils 50 at the central coil, which does not move. 'I'he series circuit, as at present used, thus begins at the central Y coil 50, passes through half the coils, by way of the exible connectors |8I, to one end of the pantograph, then returns, via the ilexible conductor 208, mounted on the pantograph. to the other end of the line of coils, and returns through the remaining coils and the leads IUI to the center again. A

One end of a cable'18 ls fastened at 59 to the left-hand side of the lowermost slide 38, as viewed n Fig. 1. The cable 18 extends over an idler pulley 88, an actuating pulley 8| and an idler pulley 82. to the uppermost slide 38, to which it is fastened at 12. A second cable 83, fastened at one end to the said uppermost slide 38 at 54, passes over idler pulleys 55 and 85, and its other end is fastened to .the lowermost slide 38 at 81. The actuating pulley 8| may be manipulated by a handle 88 to expand and contract the pantograph.

Modifications will obviously occur to persons skilled in the art, and all'such areconsidered to fall within the spirit .and scope of the invention. as defined in the-.appended claims.

What is claimed is:

1. In a system of parallel retardation paths, each comprising a linear transmission member and each equipped with vibratory terminal apparatus for intercommunicating energy with a mission member at ing, in combination, a plurality of transducersy adapted to be positioned in a sound-conveying medium and to cooperate in directionally intercommunicating energy with the medium. a transmission member aflixed in sound-communicating relation to each transducer, a movable interactor cooperative with each transmission member, the interactors being disposed along a substantially straight line, each of said transmission members being adapted to transmit energy along its length at a definite velocity to enable each transmission member and its associated interactor to cooperate to introduce a predetermined phase ,displacement between transducer and interactor, and means comprising a pantograph for simultaneously adjusting the interactors to predetermined positions along the several transmission members to enable the combination of interactors, transmission members and transducers, by introducing predetermined phase retardations of the said energy transmitted in the lseveral transmission members, to cooperate for directional energy communication with said medium.

3. Apparatus of the character described having, in combination, a plurality o! transducers adapted to be positioned in a sound-conveying medium and to cooperate in directionally intercommunicating energy with the medium, a substantially straight transmission member aflix'ed in sound-oommunicating relation to each transyducer, the transmission member being substantially parallel to one another, -a movable interactor cooperative with each transmission member, each of ',said transmission members being adapted to transmit energy along its length at a definite velocity to enable each transmission member and its associated interactor to cooperate to introduce a predetermined phase displacement between transducer and interactor, a substantially straight guide for each interactor, the guidesr being substantially. parallel to the transmission members, the interactors being disposed along a substantially straight line, and means comprising a pantograph for simultaneously adjusting the interactors along their respective guides to predetermined positions along the several transmission members without' disturbing their substantially linear relation to enable the combination of interactors, transmission members and transducers. by introducing predeter- 'mined phase retardations of the said energy transmitted in the several transmission members, to cooperate for directional energy communication with said medium.

aoeaoas 4. Apparatus of the character described having, in combination, a plurality o! transducers adapted to be positioned in a sound-conveying medium an'd to cooperate in directionally intercommunlcating energy with the medium, the

velocity to enable each; transmission member and its associated interactor to cooperate to introduce apredetermlned phase displacement between transducer group and interactor, and means for simultaneously adjusting the interactors to predetermined positions along the several transmission members to enable the combination of interactors, transmission members and transducers, by introducing predetermined and interdependent phase retardations of the said energy transmitted in the several transmission members, to cooperate for directional energy communication with said medium.

' 5. Apparatus of the character described having, in combination, a plurality of transducers adapted to be positioned along a substantially straight line in a sound-conveying medium in which the phase of vibration of the sound is progressively different from transducer to transducer, a substantially straight transmission member aixed in sound-communicating relation to each transducer, an adjustable interactor cooperative with each transmission member, the interactors being disposed along a substantially straight line, each of said transmission members being adaptedw to transmit energy along its length at a predetermined velocity to enable each transmission member and its associated interactor to cooperate to introduce a predetermined phase difference between each transducer and its corresponding interactor, and means comprising a pantograph for simultaneously adjusting the interactors along their corresponding transmission members, without disturbing their substantially straight-line relation, to predetermined positions such that, owing to the time of travel of the energy along the transmission members betweenl each transducer and its corresponding interactor, vibration peaks whichoccur at the same instant of time at the predetermined positions occur at the said progressively different times at the corresponding transducers, whereby the said progressive diierences in phase of vibration of the sound from transducer to transducer is compensated for or produced by the progressively different times of travel in the said transmission members between the transducers and their corresponding interactors.V

GEORGE W..PIERCE. ATHERTON NOYES, Jn. 

